The present invention relates to polysaccharide derivatives which contain substitutents which are the reaction product of an aromatic aldehyde group present on the polysaccharide and selected reagents containing no more than one free primary amine group.
Dialdehyde starches are known. Their major uses reflect the reactive nature of the polymeric polyaldehyde in cross-linking substrates containing amino, hydroxyl, and imino groups. See U.S. Pat. No. 3,706,633 (issued Dec. 19, 1972 to E. Katchalski et al.) which discloses the condensation of a dialdehyde starch with an alkylene diamine to produce a highly crosslinked polymeric product which is then reduced, diazotized, and coupled with an active enzyme. Japanese Kokai No. 57,202,362 (published on Dec. 11, 1982 - CA 98:200152m) discloses water resistant aqueous adhesive compositions containing starch or a starch derivative containing at least two aldehyde groups (e.g., starch dialdehyde) and a compound containing at least two isocyanate groups (e.g., polymethylene-polyphenylene polyisocyanate).
The present invention also relates to a method for preparing glass fibers and in particular to the application of a forming size to continuous filament glass fiber strands.
Glass fibers are produced by a means whereby a molten glass composition is flowed or pulled through tiny orifices or tips in a heated platinum bushing. The individual glass filaments are passed through a sizing bath, grouped into a strand, and then wound on a rapidly rotating forming tube. A size is applied to the filaments in order to bind them together, maintain the integrity of the strand during winding and unwinding, as well as facilitate eventual processing. The strand on the forming tube is thereafter placed in an oven to dry or is allowed to air dry to reduce the moisture content of the strand.
Many different compositions have been used as glass forming sizes. Typically, the sizes have comprised aqueous dispersions of various modified and unmodified starches and oils. The following patents are directed to such compositions:
U.S. Pat. No. 3,227,192 (issued Jan. 4, 1966 to D. Griffiths) discloses an aqueous forming size containing an amylose starch mixture containing approximately equal portions of a high amylose starch component having an amylose content of about 50-60% and a low amylose starch component having an amylose content of about 20-30%.
U.S. Pat. No. 3,167,468 (issued Jan. 26, 1965 to J. Lovelace et al.) discloses an aqueous forming size containing a starch ether or ester which is the reaction product of starch and a tertiary or quaternary amine.
U.S. Pat. No. 3,481,771 (issued Dec. 2, 1969 to A. Doering) discloses an aqueous forming size dispersion having a low metallic ion content which employs an uninhibited or inhibited (i.e., crosslinked) starch ether or ester derivative. Among the applicable starch esters are acetates, propionates, butyrates, laurates, stearates and oleates. Suitable crosslinking agents include aliphatic dihalides, ether forming epoxy halogen compounds (i.e., epichlorohydrin), polyfunctional reagents (i.e., phosphorus oxychloride, mixed anhydrides, and succinic anhydride).
U.S. Pat. No. 3,615,311 (issued Oct. 26, 1971 to R. Ignatius) discloses a forming size containing a cationic starch ether or ester and an underivatized starch that is preferably high in amylose.
U.S. Pat. Nos. 3,664,855 and 3,793,065 (issued May 23, 1972 and Feb. 19, 1974, respectively, to A. Morrision et al.) employ starch ethers and esters of a substituted or unsubstituted monocyclic 5 or 6 member hydrocarbon ring in a glass forming size composition.
U.S. Pat. No. 3,928,666 (issued Dec. 23, 1975 to Morrison et al.) employs a starch ester of a C.sub.4 -C.sub.6 isoalkanoic acid in a glass forming size composition.
U.S. Pat. No. 4,166,872 (issued Sept. 4, 1979 to R. Karpik et al.) is directed to a migration-resistant forming size which contains a portion of swollen but unburst partially cooked starch granules, preferably from a high amylose corn hybrid.
U.S. Pat. No. 4,168,345 (issued Sept. 18, 1979 to B. de Massey at al.) is directed to a glass forming size composition containing both a modified starch of low viscosity and an acrylic polymer film-forming agent. The useful starch is modified by treatments including etherification, esterification, cationization or acid hydrolysis.
There is always a need for new polysaccharide derivatives, especially derivatives containing silane groups, which are useful for glass forming sizes with improved adhesion to glass.